We are trying to find a way to get the previews of the images and files uploaded in SharePoint 2016 onedrive/mysite on premise. When I connect my site through one drive app on iOS I can see the preview but not in Android or in browser. I tried capturing the network calls, and found there is method call like /_layouts/15/getpreview.ashx, but when I try accessing it gives 500 internal server error. If anyone can get some input from your technical expert to find a way to get the thumbnail preview of the files uploaded on my shared document library on onedrive/mysite on-premise sp2016.